The present invention relates generally to phase change ink printers, and the apparatus and method for feeding ink into the printer, and particularly relates to key plate openings for feeding solid ink sticks into the printer.
Ink jet printers eject ink onto an image receiving medium, such as paper or an image drum, in controlled patterns of closely spaced dots that form an image. To form color images, multiple arrays of ink jet channels are used, with each array being supplied ink of a different color from an associated ink supply. Both thermal-type ink jet print heads, which eject a drop by heating the ink to form a bubble, and impulse-type ink jet print heads, which eject a drop by compressing a chamber, are common.
Solid ink or phase change ink printers conventionally receive ink in a solid form and convert the ink to a liquid form for jetting onto the image receiving medium. The printer receives the solid ink either as pellets or as ink sticks in a feed channel. With solid ink sticks, the solid ink sticks are either gravity fed or spring loaded through the feed channel toward a heater plate. The heater plate melts the solid ink into its liquid form. In a printer that receives solid ink sticks, the sticks are either gravity fed or spring loaded into a feed channel and pressed against a heater plate to melt the solid ink into its liquid form. U.S. Pat. No. 5,734,402 for a Solid Ink Feed System, issued Mar. 31, 1998 to Rousseau et al.; and U.S. Pat. No. 5,861,903 for an Ink Feed System, issued Jan. 19, 1999 to Crawford et al. describe exemplary systems for delivering solid ink sticks into a phase change ink printer.